Non-Contact Conveying Device Using Superconducting Magnetic Levitation

Abstract

A non-contact conveying device (10) using superconducting magnetic levitation capable of stably conveying an object (11), including: a conveying table (12) having a bottom with permanent magnets (16-19) to convey the object (11); a conveying guide unit (13) having superconductors (20) immediately below the respective magnets (16-19); distance sensors (21) on the conveying guide unit (13) for detecting a distance between the conveying table (12) and the conveying guide unit (13); damping coils (25) in the conveying guide unit (13) for generating a magnetic field upon energization thereof to damp vibration of the conveying table (12); and a control device (27) for detecting vibration of the conveying table (12) by signals from the distance sensors (21) and for controlling current applied to the damping coils (25). If disturbance occurs on the object (11) conveyed contactlessly by the superconducting magnetic levitation, the vibration is stopped within a short period of time.

Description

TECHNICAL FIELD [0001] The present invention relates to a device for non-contact (or isolated) transfer of, e.g., semiconductor chips or precision components in an airtight room (including a particular-gas atmosphere chamber and a vacuum chamber) or in an isolated room having temperatures different from external air, samples in a sterile room, or other objects including components, finished products, liquid or solid matter, animals, and plants. BACKGROUND ART [0002] Currently, semiconductors must be produced in a clean vacuum chamber where even presence of micron-sized dust is not permissible. A clean room robot which does not generate dust needs to be employed to transfer silicon wafers in the vacuum chamber, and it is desirable that the wafers are isolated from a semiconductor-manufacturing device during transfer and all processing steps are completed in the hermetically sealed vacuum chamber. [0003] To transfer objects inside such a vacuum or airtight chamber by handling the obje...

AI Technical Summary

Benefits of technology

[0012] In the device of the present invention, it is preferable that the permanent magnets provided to the conveying table are arranged in a Halbach array so that magnetic poles of the permanent magnets are directed only downward of the conveying table. Accordingly, magnetic fluxes of the permanent magnets can be utilized more effectively. Furthermore, the magnetic fluxes do not leak toward the conveying table, which means that the object to be conveyed is not affected by the magnetic field.

[0013] In the device of the present invention, it is preferable that the control device substantially comprises a circuit for performing differential (derivative) control of a distance between the conveying table and the conveying guide unit detected by the distance sensor. When the conveying table having the permanent magnets is located over the superconductors, the permanent magnets float over the superconductors due to the pinning effect. When the superconductors mo

Problems solved by technology

Currently, semiconductors must be produced in a clean vacuum chamber where even presence of micron-sized dust is not permissible.

In the technology disclosed in the publication, however, when disturbance such as impact

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